Continuous laundry dryer

ABSTRACT

A continuous laundry dryer which utilizes a series of selfcontained laundry dryer units, having open ends so that laundry may pass progressively through the dryer units. Conveyors deliver laundry to the initial dryer unit and remove the laundry discharged by the final dryer unit. Yieldable closure rollers overlie the conveyors and tend to conform to the laundry as it passes over the conveyors on entering or leaving the dryer. The dryer units are mounted on an angularly adjustable frame to increase or decrease the rate of movement of laundry through the dryer units. In addition, the dryer units are capable of individual angular adjustment.

United 1 States Patent 11 1 1111 3,815,257 Freze 1 June 11, 1974 1 CONTINUOUS LAUNDRY DRYER 3.601.903 8/1971 FTCZCI, 34/133 lnventorz. ni H. Freze Garden Grove, 3,659,551 5/1972 McKlnstry 34/242 Cahf Primary Examiner-Kenneth W. Sprague [73] Assignee: Challenge-Cook Br0s., Incorporated, sista a ine -James C. Yelmg Industry, Calif. Attorney, Agent, or Firm-Lyon & Lyon PP 347,792 A continuous laundry dryer which utilizes a series of 1 self-contained laundry dryer units, having open ends [52] Us CL 34/129 34/133 34/242 so that laundryv may pass progressively through the In. CL F26b 11/02 dryer units. Conveyorsdeliver laundry to the initial [58] Field of 128442 dryer unit and remove the laundry discharged by the 34/242 final dryer unit. Yieldable closure rollers overlie the conveyors and tend to conform to the laundry as it [56] References Cited passes over the conveyors on entering or leaving the 1 dryer. The dryer units are mounted on an angularly UNITED STATES PATENTS adjustable frame to increase or decrease the rate of 2,463,683 3/1949 Fay movement of laundry through the dryer units 'ln addi- 7/1952 Fwd 34/141 tion, the dryer units are capable of individual angular 3,234,661 2/1966 Nerge 34/242 ad-ustmem 3,509,639 5/1970 Arendt 34/129 1 1 3,594,918 7/1971 Quester et 'al. 34/131 8 Claims, 9 Drawing Figures PATENTEDJUH 11 I874 3815257 sum 10F 2 0 00002700000 OOOOOOOOOO CONTINUOUS LAUNDRY DRYER Laundry has usually been dried in batches. Examples of batch dryers are disclosed in my previous US. Pat. Nos. 3,419,969, and 3,601,903. In the operation of this type of tumbler dryer, a batch of laundry is inserted through an end door, the door is closed and the dryer operated for a period calculated to dry the laundry completely or to terminate drying when a desired percent of the moisture has been removed. The dooris then opened and thelaundry removed. Often two doors are used one for loading and one for unloading. Also the dryer is tilted to aid the loading or unloadingoperatron.

In large laundry operations, it is desired to reduce handling costs and to reduce the drying time by use of a continuous dryer in which the laundry is continuously or intermittently introduced at one end for removal at the other end while the dryer continues to operate. Such a continuous dryer is disclosed in US. Pat. No. 3,543,415.

If subsequent processing, such as ironing be desired, it is essential that the residual moisture content be accurately controlled, and its equally essential, that, if the laundry is to be dried, excess temperature be avoided. This has been a major problem in theopera tion of continuous .dryers, tending to limit severly the material which can be safely treated by continuous dryers.

In some instances conventional batch dryers have been placed in tandem, but the problem of transfer from one unit to the next has interfered with proper control of drying cycle.

SUMMARY OF THE INVENTION The present invention is directed to a continuous laundry dryer which provides for accurate control of the drying operation and is summarized in the following objects:

First, to provide a continuous laundry dryer which utilizes a series of batch dryers of the type disclosed in my US. Pat. Nos. 3,419,969 and 3,601,903 in which the doors are omitted and the dryer arranged as units in end-'to-end relation; each unit having a separate heating and circulation system permitting individual control.

Second, to provide a continuous laundry dryer as indicated in the preceeding object, wherein the dryer units are mounted on a common frame capable of angular adjustment to control the rate of movement of the laundry through the dryer from the intake to the discharge end of the dryer.

Third, to provide a continuous laundry dryer as indicated in the preceeding objects wherein the dryer units may be disposed in angular relation to each other thereby tocontrol the role of movement in each dryer unit individually; so as to provide, forexample, a faster movement of laundry in the final dryer unit as compared to the preceeding dryer units.

Fourth, to provide a continuous laundry dryer which incorporates a novel closure at its entrance end and its discharge end, each overlying a conveyor and including a yieldable roller tending to conform to the laundry carried to the laundry carried by the conveyor.

Fifth, to provide a continuous laundry dryer, a modification of which incorporates a novel means for producing a curtain of air between dryer units tending to isolate the circulation of air in each unit from the adjacent unit or units.

DESCRIPTION or THE FIGURES FIG. .1 is an essentially diagrammatical plan view of the continuous laundry dryer.

7 FIG. 2 is an essentially. diagrammatical longitudinal sectional view thereof taken through 2-2 of FIG. 1.

FIG. 3 is an enlarged fragmentary sectional view taken within circle 3 of the. FIG. 2..

FIG. 4 is an enlarged fragmentary view partially in section taken within .circle.4 ofFIG. 2.

FIG. 5 is an enlarged transverse sectional view taken through 55 of FIG. 2.

FIG. 6 is a fragmentary sectional view taken through 6-6 of FIG. 1.

FIG. 7 is a transverse sectional view taken through FIG. 7-7 of FIG. 2 to indicate the location of an air' curtain means which may be added. to the construction shown in FIG. 2..

FIG. 8 is an essentially diagrammatical fragmentary sectional view through 88 of FIG. 2 suggesting the compliant property of the laundry engaging roller.

FIG; 9 is a fragmentary essentially diagrammatical view showing a modified inlet ,to the continuous dryer.

The continuous laundry dryer includes a base frame 1, one end of which is connected to a pivot support 2 and the other end of which is connected to a jack support 3 so that the base frame may be angularly adjusted. a

Mounted on the base frame 1 in the construction, illustrated are three dryer units 4, .5 and 6. The dryer units are in tandem, that is, in end-to-end relation. Except for the changes required in order to mount the dryer units in tandem relation such as removal of their end doors, each dryer unit is essentially the same as the dryer disclosed in the aforementioned previous US. Pat. Nos. 3,419,969 and 3,601,903.

Each dryer unit includes a fixed cylindrical outer shell 7 having annular end walls 8. The initial dryer unit 4 is disposed on the base frame at its end having the jack support 3. The upper portion of the outer shell 7 of each dryer unit is covered by a semicircular entrance duct 9 and the shell is provided with a slot 10 and perforations 11 for passage of air into the shell. The entrance duct 9 is connected to a vertically directed air intake 12 which receives heated air from a heater or burner 13 connected to a blower 14. The bottom side of each shell 7 communicates with a discharge chamber 15 connected to a discharge duct 16 which may be provided with a suction fan 17.

Suitably journaled within each shell 7 as more fully disclosed in the aforementioned patents is a rotatable drum 18, the major portion of which is cylindrical and joined to frusto-conical end portions 19 and forms internally a drying zone.-The drum 18 including its end portions is provided with perforations20 so that air entering the upper side of the shell 7 passes through the drum and into the discharge chamber located under the shell.

Each dryer unit is provided with a mounting frame 21 which is joined by adjustable screws or other means 22 to the base frame 1 so that each dryer unit may be posi tioned in predetermined angular relation to the base frame.

One of the end walls 8 of the initial dryer unit 4 is provided with an inlet opening 23 to receive laundry. This end wall is enclosed in an inlet hood 24 closed at its lower side by a belt conveyor 25. The hood 24 forms with the conveyor 25 an entrance end 26 which receives a closure 27. The closure 27 includes a hinged panel 28, at the lower end of which is journaled a large compliant roller 29 which engages and conforms to laundry carried by the conveyor 25 into the initial dryer unit. as suggested in FIG. 8. The roller is joined of soft porous plastic material covered by a skin 29a and complies or conforms to the laundry indicated by 2312. Alternatively the roller may be an inflated cylinder provided with suitable webs, not shown, to maintain an essentially cylindrical shape until pressed inwardly by the laundry. A supply conveyor 30 delivers the laundry to the conveyor 25.

The confronting end walls of the dryer units 4, and 6 are spaced slightly and this space is closed by a sealing ring 31, omitted from FIG. 2, but shown in FIG. 3. Because of the small scale of the drawings, the spacing between dryer units is exaggerated. Also the preceeding dryer unit is provided with a cylindrical bridging ring 32 forming an opening to communicate with the succeeding dryer unit.

The final dryer unit 6 is provided with an outlet opening 33 which is enclosed by an outlet hood 34 having at its lower side a belt conveyor 35. The outlet hood 34 is provided with a discharge end 36 which receives a closure 37 comprising hinged panel 38 and a compliant roller 39.

The discharge duct 16 of the final dryer unit 6 is connected by a branch duct 40 to the outlet hood 34. A diverter vane 41 is located at the entrance end of the branch duct 40 so that the corresponding suction fan 17 may be connected either to the discharge duct 16 or to the branch duct 40.

Operation of the continuous laundry dryer is as follows:

Laundry to be dried is delivered on the conveyor 30. The laundry may be separated pieces or may be delivered in bundles which have been compressed to squeeze out excess water. In the latter case the conveyor 25 and the lower side of the inlet opening 23 may be lowered to permit passage of a bundle into the initial dryer unit 4 as indicated by broken lines in FIG. 2.

The initial dryer unit 4 is set into operation before receiving the laundry; that is, rotation of its drum is commenced and heated air is circulated. The remaining dryer units 4 and 5 are also started either simultaneously with the dryer unit 4 or in sequence.

The laundry is continuously or intermittently fed into the first drum and tends, by reason of the frusto-conical end portions 19, to remain in the drum until the quantity of laundry approaches the capacity of the drum. AS the volume of laundry increases the perforations 20 are progressively closed by the increasing quantity of laundry. This is particularly true of those perforations passing over the discharge chamber so that hot air is admitted but its discharge through the discharge chamber 15 and to the suction fan 17 is impeded. The subsequent dryer unit 5 which has not as yet received laundry contains air at a reduced pressure by reason of free flow into the discharge chamber 15 and through the fan 17. As a result there is a flow of air from the dryer unit 4 to the dryer unit 5 which carries with it the laundry. As the laundry accumulates in the dryer unit 5 there is again a build-up of pressure in the dryer unit 5 causing transfer to the dryer unit 6.

Equilibrium tends to be established when the laundry is distributed through the three dryer units. The larger amount of laundry being in the initial unit 4, a lesser amount in unit 5 and a still lesser amount in unit 6. If the dryer units shared a common axis which was horizontal, control of the transfer of laundry from the initial dryer unit 4 to the final dryer unit 6 would be difficult particularly if its desired to effect a partial drying of the laundry. By adjusting the base frame 1 so that the dryer units are inclined, the rate of transfer may be controlled; that is, the greater the incline of the base frame the more rapid will be'the progress of laundry through the series of dryers.

A further control over the axial movement of the laundry is attained by individually adjusting the dryer units relative to the average incline determined'by the base frame 1. This adjustment is accomplished by the adjustment screws 22. For purposes of illustration the angular relationship between the dryer units has been exaggerated.

Tests have indicated that, to effect a dry condition of the discharged laundry, thebase frame may be inclined 0 49'. The initial dryer unit 4 is disposed with its axis horizontal; that is, relative to the base frame its angle is 0 49 in the opposite direction. The second dryer unit 5 is inclined 0 14' with respect to the horizontal; that is, 0 35 with respect to the frame and the final dryer unit 6 is inclined 2 06' with respect to the opposite direction horizontal; that is, l 17 relative to the base frame. This angular relation between the dryer units may be maintained; then, by varying the angle of the base frame, the degree of dryness may be controlled. By raising the base frame until its angle is 1 38', for example, which increases the angles of the dryer units proportionably, the laundry as discharged from the dryer unit 6 is in a semi-dry condition. It should be understood that the indicated angles are merely representative.

During normal flow of the laundry; that is, during a period in which laundry is continuously or intermittently supplied to the dryer unit 4, the laundry contin ues to discharge from the dryer 6. This movement is aided by the increased angle of the dryer unit 6. Once the laundry is received in the outlet hood 34, it is carried by the belt conveyor 35 under the closure 37.

When it is desired to terminate operation of the dryer, the dryer is permitted to operate for a predetermined few minutes after the laundry supply is discontinned. The heater 13, the blowers l4 and 17 serving dryer unit 4 are turned off. This causes the pressure in dryer unit 4 to raise to atmospheric pressure, creating air flow which advances the laundry into dryer unit 5.

After a suitable interval, the heater l3 and blowers 14 and 17 of dryer unit 5 are shut off causing transfer of laundry into dryer unit 6. Because of the greater inclination of dryer unit 6, when the heater l3 and blowers 14 and 17 of dryer unit 6 are shut off, the laundry will continue to advance onto the conveyor 35. However, some residual laundry might remain in dryer 6, particularly light weight pieces; should the angular position of the dryer 6 be reduced, this may occur. This condition is prevented by permitting the blower 17 to continue and diverting air into duct 40, using the flap valve 41.

Further control of movement of laundry from one unit to the succeeding unit may be accomplished by providing a curtain of air between the dryer units 4 and 5 and between the dryer units 5 and'6. This may be accomplishedjby' an air curtain system 42 shown in FIG. 7. In place of the bridging ring 32, a perforated bridging ring 43 isprovided. A sealing web 44 is provided between the dryer units. The sealing web defining an upper inlet chamber 45 and a lower outlet chamber 46. The chambers are connected by a duct 48 in which is interposed, ablower 49. The air curtain systems may be operated continuously or intermittently. The effect is to reduce air transferbetween the dryer units thus delaying transferof laundry to the succeeding unit.

Reference is directed toFlG. 9, if the continuous dryer is to be used for cake or bunch loading; that is, if compressed bundles of laundry are to be fed intermittently, a hopper 50 may be used in place of the hood 22 and the conveyor 30 may discharge directly into the hopper 50. The upper side is closed by a gate 51 which may be spring biased to normally occupy a closed upper position, but movable downwardly by the weight of laundry or by a hydraulic actuator, not shown, may be used. t 1

Referring tothe frusto-conical end portions 19, and the perforations therein, air entering through the end portions tends to have an axial component which serves to retainthe laundry in each dryer unit by moving the laundry toward the axial center of the dryer unit. This is overcome by the angular position of the dryer unit or by pressure differential between dryer units. 1

While particular embodiments of this invention have been shownand described, it not intended to limit the same to the details of the constructions set forth, but instead, the invention embraces such changes, modifications and equivalents of the various parts and their relationshipsas come within the purview of the appended claims.

I claim: t I

l. A continuous laundry dryer, comprising:

a. at least a pair of dryer units, each dryer unit including a rotatable tumbler drum having an approximately horizontal axis and open at its axial ends, meansdisposed externally of the drum for introducing heated'air into the drum for contact with laundry contained within the drum, and means also disposed externally of the drum for extraction of air from the drum;

b. the dryer units being disposed in contiguous endto-end relation;

c. means for introducing laundry into one end of the series of dryer units for tumbling movement and progressive movement axially through the series of dryer units;

d. means for removing laundry from'the opposite end of the series of dryer units;

e. an angularly adjustable main base frame for supporting and angularly adjusting the dryer units in unison;

f. and an independent base frame mounted on the main base frame for supporting and adjusting each dryer unit individually.

2. A continuous laundry dryer as defined in claim 1,

to thereby cause an initial build-up of laundry in each dryer unit before movement of laundry therefrom. r

3. A continuous laundry dryer, comprising:

a. at least a pair of dryer units, each dryer unit including a rotatable tumbler drum having an approximately horizontalaxis and open at its axial ends, means disposed externally of the drum for introducing heated air into the drum for contact with laundry contained within the drum, and means also disposed externally of the drum for extraction of air from the drum;

b. the dryer units being disposed in contiguous endto-end relation; i r c. means for introducing laundry into one end of the series of dryer units for tumbling movement and progressive movement axially through the series of dryer units; i

d. means for removing laundry from the opposite end of the series of dryer units;

e. means defining an essentially planar transverse air passage between contiguous dryer units;

f. and means for circulating air through said planar air passage to form an air curtain between the contiguous dryer units.

4. A continuous laundry dryer, comprising: i j

a. a dryer structure having an. entrance end anda discharge end, and including therebetween at least a one dryer drum disposed with its axis inclined to move laundry from the entrance end toward the discharge end and means for circulating heated air through the dryer drum; f

b. and a laundry introducing means and laundry discharge means each including a tubular hood enclosing the entrance end and discharge end respectively of the dryer structure, a conveyor at the bottom side of the hood, aclosure for the hood having a frame hinged to the upper side of the hood, and a complient rollerzsuspended therefrom and dimensioned to conform substantially to laundry passing through the hood on the conveyor to or.from the dryer structure while restraining escape of air from the ends'of the dryerstructure.

5. .A continuous laundry dryer, as defined in claim 4,

wherein:

a. the dryer structure includes a series of dryer drums arranged. in tandem;

b. and means are provided to adjust the inclination of individual dryer drums.

6. A continuous laundry dryer, as defined in claim 5,

wherein:

a. the dryer drums include restricted entrance and exit ends tending to cause an initial build-up of laundry in each drum before movement of laundry to a succeeding drum.

7. A continuous laundry dryer as defined in claim 5,

wherein:

a. each dryer drum is provided with a separate heated air circulating means; I

b. the air circulating means of the final dryer drum adjacent the discharge end hood is provided with a bypass duct communicating with the discharge end hood;

c. and a valve means controls the proportion of air delivered to the final dryer drum and to the discharge end hood. 7

hood;

d. and a complient roller suspended from and complementing the closure member, the roller being dimensioned to conform substantially to laundry passing on the conveyor thereby to minimize escape of air from the dryer structure through the hood. 

1. A continuous laundry dryer, comprising: a. at least a pair of dryer units, each dryer unit including a rotatable tumbler drum having an approximately horizontal axis and open at its axial ends, means disposed externally of the drum for introducing heated air into the drum for contact with laundry contained within the drum, and means also disposed externally of the drum for extraction of air from the drum; b. the dryer units being disposed in contiguous end-to-end relation; c. means for introducing laundry into one end of the series of dryer units for tumbling movement and progressive movement axially through the series of dryer units; d. means for removing laundry from the opposite end of the series of dryer units; e. an angularly adjustable main base frame for supporting and angularly adjusting the dryer units in unison; f. and an independent base frame mounted on the main base frame for supporting and adjusting each dryer unit individually.
 2. A continuous laundry dryer as defined in claim 1, wherein: a. the dryer unit drums taper at selected axial extremities to provide end openings reduced in diameter, to thereby cause an initial build-up of laundry in each dryer unit before movement of laundry therefrom.
 3. A continuous laundry dryer, comprising: a. at least a pair of dryer units, each dryer unit including a rotatable tumbler drum having an approximately horizontal axis and open at its axial ends, means disposed externally of the drum for introducing heated air into the drum for contact with laundry contained within the drum, and means also disposed externally of the drum for extraction of air from the drum: b. the dryer units being disposed in contiguous end-to-end relation; c. means for introducing laundry into one end of the series of dryer units for tumbling movement and progressive movement axially through the series of dryer units; d. means for removing laundry from the opposite end of the series of dryer units; e. means defining an essentially planar transverse air passage between contiguous dryer units; f. and means for circulating air through said planar air passage to form an air curtain between the contiguous dryer units.
 4. A continuous laundry dryer, comprising: a. a dryer structure having an entrance end and a discharge end, and including therebetween at least one dryer drum disposed with it''s axis inclined to move laundry from the entrance end toward the discharge end and means for circulating heated air through the dryer drum; b. and a laundry introducing means and laundry discharge means each including a tubular hood enclosing the entrance end and discharge end respectively of the dryer structure, a conveyor at the bottom side of the hood, a closure for the hood having a frame hinged to the upper side of the hood, and a complient roller suspended therefrom and dimensioned to conform substantially to laundry passing through the hood on the conveyor to or from the dryer structure while restraining escape of air from the ends of the dryer structure.
 5. A continuous laundry dryer, as defined in claim 4, wherein: a. the dryer structure includes a series of dryer drums arranged in tandem; b. and means are provided to adjust the inclination of individual dryer drums.
 6. A continuous laundry dryer, as defined in claim 5, wheRein: a. the dryer drums include restricted entrance and exit ends tending to cause an initial build-up of laundry in each drum before movement of laundry to a succeeding drum.
 7. A continuous laundry dryer as defined in claim 5, wherein: a. each dryer drum is provided with a separate heated air circulating means; b. the air circulating means of the final dryer drum adjacent the discharge end hood is provided with a bypass duct communicating with the discharge end hood; c. and a valve means controls the proportion of air delivered to the final dryer drum and to the discharge end hood.
 8. A closure means for a continuous laundry dryer structure having an open entrance end and a discharge end and including therebetween a dryer drum means adapted to move laundry from the entrance to the discharge end, said closure means comprising: a. a hood continuing from an end of the dryer structure; b. a conveyor at the under side of the hood; c. a closure member hinged to the upper side of the hood; d. and a complient roller suspended from and complementing the closure member, the roller being dimensioned to conform substantially to laundry passing on the conveyor thereby to minimize escape of air from the dryer structure through the hood. 